Package org.apache.hadoop.hdfs.server.namenode

Class CacheManager

java.lang.Object

org.apache.hadoop.hdfs.server.namenode.CacheManager

@LimitedPrivate("HDFS")
public class CacheManager
extends java.lang.Object

The Cache Manager handles caching on DataNodes. This class is instantiated by the FSNamesystem. It maintains the mapping of cached blocks to datanodes via processing datanode cache reports. Based on these reports and addition and removal of caching directives, we will schedule caching and uncaching work.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CacheManager.PersistState

Field Summary

Fields

Modifier and Type	Field	Description
static org.slf4j.Logger	LOG

Method Summary

Modifier and Type	Method	Description
org.apache.hadoop.hdfs.protocol.CachePoolInfo	addCachePool(org.apache.hadoop.hdfs.protocol.CachePoolInfo info)	Create a cache pool.
org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo	addDirective(org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo info, FSPermissionChecker pc, java.util.EnumSet<org.apache.hadoop.fs.CacheFlag> flags)
void	clearDirectiveStats()
org.apache.hadoop.util.GSet<CachedBlock,CachedBlock>	getCachedBlocks()
java.util.Collection<CacheDirective>	getCacheDirectives()
java.util.Collection<CachePool>	getCachePools()
java.lang.Thread	getCacheReplicationMonitor()
long	getMaxLockTimeMs()
long	getSleepTimeMs()
boolean	isCheckLockTimeEnable()
boolean	isEnabled()
org.apache.hadoop.fs.BatchedRemoteIterator.BatchedListEntries<org.apache.hadoop.hdfs.protocol.CacheDirectiveEntry>	listCacheDirectives(long prevId, org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo filter, FSPermissionChecker pc)
org.apache.hadoop.fs.BatchedRemoteIterator.BatchedListEntries<org.apache.hadoop.hdfs.protocol.CachePoolEntry>	listCachePools(FSPermissionChecker pc, java.lang.String prevKey)
void	loadState(CacheManager.PersistState s)
void	loadStateCompat(java.io.DataInput in)	Reloads CacheManager state from the passed DataInput.
void	modifyCachePool(org.apache.hadoop.hdfs.protocol.CachePoolInfo info)	Modify a cache pool.
void	modifyDirective(org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo info, FSPermissionChecker pc, java.util.EnumSet<org.apache.hadoop.fs.CacheFlag> flags)
void	processCacheReport(org.apache.hadoop.hdfs.protocol.DatanodeID datanodeID, java.util.List<java.lang.Long> blockIds)
void	removeCachePool(java.lang.String poolName)	Remove a cache pool.
void	removeDirective(long id, FSPermissionChecker pc)
CacheManager.PersistState	saveState()
void	saveStateCompat(java.io.DataOutputStream out, java.lang.String sdPath)	Saves the current state of the CacheManager to the DataOutput.
void	setCachedLocations(org.apache.hadoop.hdfs.protocol.LocatedBlocks locations)
void	startMonitorThread()
void	stopMonitorThread()
void	waitForRescanIfNeeded()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

LOG

public static final org.slf4j.Logger LOG

Method Detail

isEnabled

public boolean isEnabled()

isCheckLockTimeEnable

public boolean isCheckLockTimeEnable()

getMaxLockTimeMs

public long getMaxLockTimeMs()

getSleepTimeMs

public long getSleepTimeMs()

startMonitorThread

public void startMonitorThread()

stopMonitorThread

public void stopMonitorThread()

clearDirectiveStats

public void clearDirectiveStats()

getCachePools

public java.util.Collection<CachePool> getCachePools()

Returns:

Unmodifiable view of the collection of CachePools.

getCacheDirectives

public java.util.Collection<CacheDirective> getCacheDirectives()

Returns:

Unmodifiable view of the collection of CacheDirectives.

getCachedBlocks

@VisibleForTesting
public org.apache.hadoop.util.GSet<CachedBlock,CachedBlock> getCachedBlocks()

addDirective

public org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo addDirective(org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo info,
                                                                       FSPermissionChecker pc,
                                                                       java.util.EnumSet<org.apache.hadoop.fs.CacheFlag> flags)
                                                                throws java.io.IOException

Throws:

java.io.IOException

modifyDirective

public void modifyDirective(org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo info,
                            FSPermissionChecker pc,
                            java.util.EnumSet<org.apache.hadoop.fs.CacheFlag> flags)
                     throws java.io.IOException

Throws:

java.io.IOException

removeDirective

public void removeDirective(long id,
                            FSPermissionChecker pc)
                     throws java.io.IOException

Throws:

java.io.IOException

listCacheDirectives

public org.apache.hadoop.fs.BatchedRemoteIterator.BatchedListEntries<org.apache.hadoop.hdfs.protocol.CacheDirectiveEntry> listCacheDirectives(long prevId,
                                                                                                                                              org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo filter,
                                                                                                                                              FSPermissionChecker pc)
                                                                                                                                       throws java.io.IOException

Throws:

java.io.IOException

addCachePool

public org.apache.hadoop.hdfs.protocol.CachePoolInfo addCachePool(org.apache.hadoop.hdfs.protocol.CachePoolInfo info)
                                                           throws java.io.IOException

Create a cache pool. Only the superuser should be able to call this function.

Parameters:

info - The info for the cache pool to create.

Returns:

Information about the cache pool we created.

Throws:

java.io.IOException

modifyCachePool

public void modifyCachePool(org.apache.hadoop.hdfs.protocol.CachePoolInfo info)
                     throws java.io.IOException

Modify a cache pool. Only the superuser should be able to call this function.

Parameters:

info - The info for the cache pool to modify.

Throws:

java.io.IOException

removeCachePool

public void removeCachePool(java.lang.String poolName)
                     throws java.io.IOException

Remove a cache pool. Only the superuser should be able to call this function.

Parameters:

poolName - The name for the cache pool to remove.

Throws:

java.io.IOException

listCachePools

public org.apache.hadoop.fs.BatchedRemoteIterator.BatchedListEntries<org.apache.hadoop.hdfs.protocol.CachePoolEntry> listCachePools(FSPermissionChecker pc,
                                                                                                                                    java.lang.String prevKey)

setCachedLocations

public void setCachedLocations(org.apache.hadoop.hdfs.protocol.LocatedBlocks locations)

processCacheReport

public final void processCacheReport(org.apache.hadoop.hdfs.protocol.DatanodeID datanodeID,
                                     java.util.List<java.lang.Long> blockIds)
                              throws java.io.IOException

Throws:

java.io.IOException

saveStateCompat

public void saveStateCompat(java.io.DataOutputStream out,
                            java.lang.String sdPath)
                     throws java.io.IOException

Saves the current state of the CacheManager to the DataOutput. Used to persist CacheManager state in the FSImage.

Parameters:

out - DataOutput to persist state

sdPath - path of the storage directory

Throws:

java.io.IOException

saveState

public CacheManager.PersistState saveState()
                                    throws java.io.IOException

Throws:

java.io.IOException

loadStateCompat

public void loadStateCompat(java.io.DataInput in)
                     throws java.io.IOException

Reloads CacheManager state from the passed DataInput. Used during namenode startup to restore CacheManager state from an FSImage.

Parameters:

in - DataInput from which to restore state

Throws:

java.io.IOException

loadState

public void loadState(CacheManager.PersistState s)
               throws java.io.IOException

Throws:

java.io.IOException

waitForRescanIfNeeded

public void waitForRescanIfNeeded()

getCacheReplicationMonitor

@VisibleForTesting
public java.lang.Thread getCacheReplicationMonitor()